WO2018205841A1 - Method for preparing mesoporous nay-type zeolite molecular sieve - Google Patents

Abstract

A method for preparing a mesoporous NaY-type zeolite molecular sieve comprises the following steps: 1) mixing a silicon source, an aluminum source and water in a temperature ranging from 25ºC to 35ºC, adjusting a ph to 9 to 12, dropping an NaY-type molecular sieve directing agent, and then gradually and dropwise adding an organic quaternary ammonium salt serving as a template, so as to obtain aluminosilicate gel; 2) crystallizing the aluminosilicate gel; and 3) roasting a production obtained in step 2) to remove the template. The obtained molecular sieve has a crystallized pore wall structure, the defect of a single pore structure is avoided due to a zeolite molecular sieve of a hierarchical pore structure, is a very valuable catalysis material, and especially has a broad application prospect in reactions that involve in macromolecules and that are limited by diffusion. In the method, the tetradecyl dimethyl benzyl ammonium chloride organic quaternary ammonium salt is used as a mesoporous template, and a new template is provided for the preparation of the mesoporous NaY-type zeolite molecular sieve.

Description

Method for preparing mesoporous NaY zeolite molecular sieve Technical field

The invention relates to a catalyst carrier, in particular to a method for preparing a medium pore NaY zeolite molecular sieve.

Background technique

The NaY type molecular sieve has a Si/Al ratio of generally 1.5 to 3. It belongs to a faujasite type (FAU) molecular sieve and has a three-dimensional twelve-membered ring channel structure, the orifice diameter is about 0.74 nm, and the inner cavity size is about 1.3 nm. . Due to its unique pore structure, suitable acidity and thermal stability, NaY molecular sieves are widely used in the petrochemical industry, especially in the fluid catalytic cracking (FCC) reaction. However, due to the relatively narrow pore structure of the NaY zeolite molecular sieve, it is difficult for the heavy oil molecules with large diameter to enter the pores with a pore diameter of only about 0.74 nm, and the active center of the inner surface of the zeolite has no effect on the reaction, which greatly reduces the activity. In addition, the smaller pore size also increases the mass transfer resistance of the reactants and products, so that the reaction product cannot be diffused and deposited on the surface of the catalyst to form carbon deposits in time, thereby reducing the catalytic activity. Therefore, the smaller pore size limits the use of microporous zeolites in reactions involving macromolecules.

Mesoporous materials, such as MCM-41s, have a larger pore size advantage than conventional zeolite molecular sieves, allowing larger diameter molecules to enter the pores and catalyzing reactions involving macromolecules. On the other hand, a larger pore size reduces the mass transfer resistance and facilitates the diffusion of reactants and products. However, due to the amorphous pore wall structure of mesoporous molecular sieves, their acidity and hydrothermal stability are poor, especially compared to microporous zeolites, which limits their use in catalysis.

In order to overcome the limitations of microporous zeolite and mesoporous molecular sieves, many researchers are looking for a new material that combines the advantages of both microporous zeolite and mesoporous materials, with high hydrothermal stability and high acid strength. It also contains a large pore size, which makes the two complementary advantages, and can be widely used in the field of catalysis. Karlsson Arne et al. added the mesoporous templating agent cetyltrimethylammonium bromide (CTAB) to a coagulation solution of synthetic MFI zeolite containing tetrapropylammonium (TPA), which is expected to lead to the formation of mesoporous structures. And the microporous template TPA can guide the formation of micropores on the mesoporous wall to form a composite molecular sieve having a micro mesoporous structure. In reality, however, the two templating agents are competing with each other to form a mixture of mesoporous materials and microporous materials. In 2008, Fan Wei et al. prepared a three-dimensional ordered mesoporous (3DOm) carbon hard template with adjustable pore size, and successfully synthesized ordered nanocrystals using the hard template to produce intercrystalline mesopores. These research results have realized the pore structure of multi-stage pore molecular sieve. The material contains both mesopores and crystallized pore wall structures. However, these methods have the disadvantages of high synthesis cost and complicated preparation steps, which are not conducive to industrial production.

Summary of the invention

The object of the present invention is to provide a preparation method of a medium pore NaY type zeolite molecular sieve. The medium pore NaY type zeolite molecular sieve prepared by the method has large specific surface area, excellent pore structure, simple preparation steps and low cost.

In order to achieve the above object, the technical scheme adopted by the present invention is: a preparation method of a medium pore NaY type zeolite molecular sieve, comprising the following steps:

1) First mix the silicon source, aluminum source and water at 25-35 ° C, and adjust the pH to 9 ~ 12, then add the NaY molecular sieve guide agent into the mixture evenly, stir for 3 ~ 5h, then the organic season The ammonium salt is added dropwise as a template, and stirring is continued for 0.5 to 2 hours to obtain an aluminosilicate gel, the NaY type molecular sieve directing agent, the aluminum source, the silicon source, the templating agent and the water according to the final aluminosilicate gel system. the _{Na 2 O:Al 2 O 3 :SiO 2} : molar ratio of templating agent :H ₂ O ratio of 2.0 to 4.0:0.8 1.3:8.0 ~ ~ ~ 0.36:200 9.7:0.09 added to 240;

2) the aluminosilicate gel is crystallized, the crystallization temperature is 60-90 ° C, the crystallization time is 72-120 h;

3) The product of step 2) is calcined at 500-600 ° C for 4-8 h to remove the templating agent to obtain the mesoporous NaY zeolite molecular sieve.

Further, the step 1), the preparation of zeolite NaY directing agent is as follows: sodium hydroxide, sodium aluminate, silica sol and water by _{Na 2 O:Al 2 O 3 :SiO 2} :H 2 O The mixture is uniformly mixed in a molar ratio of from 13.0 to 19.0:0.8 to 1.3:12.0 to 18.0:225.0 to 425.0, and then aged at 25 to 35 ° C for 15 to 25 hours.

Further, in the step 1), the organic quaternary ammonium salt is tetradecyldimethylbenzyl ammonium chloride.

Further, in the step 1), the aluminum source is sodium metaaluminate, aluminum sulfate or aluminum nitrate.

Further, in the step 1), the silicon source is fumed silica, water glass, silica sol or tetraethyl orthosilicate.

Further, in the step 2), after the aluminosilicate gel is crystallized, washing, filtration and drying treatment are sequentially performed.

Further, a method of preparing zeolite NaY directing agent, sodium hydroxide, sodium aluminate, silica sol and water by _{Na 2 O:Al 2 O 3 :SiO 2} :H 2 O 15.0 to 17.0: The molar ratio of 0.9 to 1.2:14.0 to 16.0:300.0 to 380.0 was mixed.

Further, the aging time is 16 to 22 hours.

Further, in the step 2), the crystallization temperature is 75 to 85 ° C, and the crystallization time is 84 to 110 h.

Further, in the step 3), the calcination temperature is 530 to 580 ° C, and the calcination time is 5 to 7 h.

Further, in the step 3), the mesoporous pore size of the mesoporous NaY type zeolite molecular sieve is concentrated at 2.5 to 8.0 nm.

Compared with the prior art, the invention has the following advantages:

First, in the present invention, a silica sol is used as a silicon source. First, a NaY zeolite molecular sieve directing agent is prepared, and then a mesoporous template is added to a sol-gel system for preparing a NaY zeolite molecular sieve, and is prepared by a low temperature hydrothermal method. The pore NaY type zeolite is calcined by crystallization to remove the templating agent to obtain a mesoporous NaY type zeolite molecular sieve. The mesoporous NaY type zeolite molecular sieve prepared by the invention has a crystalized pore wall structure, and the multi-stage pore structure zeolite molecular sieve can avoid defects of a single pore structure, and is a very valuable catalytic material, especially in the case of It has broad application prospects in reactions to macromolecules and diffusion-limited.

Secondly, the mesoporous NaY zeolite molecular sieve prepared by the invention is composed of nanometer crystal grains of different particle sizes of 200 nm to 500 nm, and the crystallinity and thermal stability of the product are good. The nano-grain makes the mesoporous NaY zeolite molecular sieve have a larger outer surface area, so that more active centers are exposed, effectively eliminating the diffusion resistance, and the catalyst efficiency is fully utilized, thereby improving the macromolecular reaction performance; It has more exposed pores and is not easily blocked by reactive deposits, which is beneficial for long reaction cycle operation.

Third, the invention adopts the hydrothermal synthesis method at a lower crystallization temperature, simplifies the synthesis step, has a simple preparation process, and the NaY type molecular sieve directing agent has good uniformity in the mixed liquid.

Fourthly, the self-made NaY type molecular sieve directing agent of the invention utilizes tetradecyl dimethyl benzyl ammonium chloride (TDBAC) organic quaternary ammonium salt as a mesoporous templating agent, and can be aggregated by using a long alkyl chain moiety. The pores form a mesoporous NaY zeolite molecular sieve, thereby providing a novel and simple and feasible template for the preparation of the mesoporous NaY zeolite molecular sieve.

DRAWINGS

Figure 1 is an X-ray diffraction diagram of a mesoporous NaY zeolite molecular sieve prepared in accordance with the present invention in comparison with a conventional microporous NaY zeolite.

2 is a scanning electron micrograph of a mesoporous NaY type zeolite molecular sieve material prepared by the present invention.

3 is a nitrogen adsorption-desorption isotherm of a mesoporous NaY type zeolite molecular sieve prepared by the present invention and a conventional microporous NaY type zeolite.

4 is a pore size distribution curve calculated by a BJH model of a mesoporous NaY type zeolite molecular sieve prepared by the present invention and a conventional microporous NaY type zeolite.

detailed description

The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

In the following examples, the crystal form and relative crystallinity of the molecular sieve were determined by XRD, and the surface area and pore structure parameters were determined by low temperature nitrogen adsorption and desorption. The specific data are shown in Table 1.

Example 1

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 1.12 g of sodium hydroxide (96 wt% NaOH, technical grade), 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 25.67 g of distilled water, 16.80 g of silica sol (30 wt% SiO) ₂ , industrial grade) mixed uniformly at 30 ° C, and then 1.84g of the guiding agent prepared in step (1) was slowly dropped into it, mixed uniformly, after stirring for 4h, then 0.74g of tetradecyl dimethyl benzyl Ammonium chloride (50 wt% TDBAC, technical grade) was added dropwise and stirring was continued for 1 h to give a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic templating agent was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-1.

Example 2

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 1.12 g of sodium hydroxide (96 wt% NaOH, technical grade), 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 25.30 g of distilled water, 16.80 g of silica sol (30 wt% SiO) ₂ , industrial grade) uniformly mixed at 30 ° C, and then 1.84 g of the guiding agent prepared in the step (1) was slowly dropped into the mixture, and uniformly mixed. After stirring for 4 hours, 1.47 g of tetradecyldimethylbenzyl group was further added. Ammonium chloride (50 wt% TDBAC, technical grade) was added dropwise and stirring was continued for 1 h to give a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic templating agent was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-2.

Example 3

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 1.12 g of sodium hydroxide (96 wt% NaOH, technical grade), 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 24.94 g of distilled water, 16.80 g of silica sol (30 wt% SiO) ₂ , industrial grade) mixed uniformly at 30 ° C, and then 1.84g of the guiding agent prepared in step (1) was slowly dropped into it, mixed uniformly, after stirring for 4h, then 2.21g of tetradecyldimethylbenzyl Ammonium chloride (50 wt% TDBAC, technical grade) was added dropwise and stirring was continued for 1 h to give a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic templating agent was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-3.

Example 4

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 5.21 mL of 2 mol/L HCl, 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 22.72 g of distilled water, 19.38 g of water glass (modulus 3.1) at 30 ° C After mixing uniformly, 1.84 g of the guiding agent prepared in the step (1) was slowly dropped into the mixture, and the mixture was uniformly mixed. After stirring for 4 hours, 1.47 g of tetradecyldimethylbenzylammonium chloride (50 wt% TDBAC, industrial) was further added. The grade was added dropwise and stirring was continued for 1 h to obtain a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic templating agent was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-4.

Example 5

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 5.21 mL of 2 mol/L HCl, 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 22.35 g of distilled water, 19.38 g of water glass (modulus 3.1) at 30 ° C After mixing uniformly, 1.84 g of the guiding agent prepared in the step (1) was slowly dropped into the mixture, and the mixture was uniformly mixed. After stirring for 4 hours, 2.21 g of tetradecyldimethylbenzylammonium chloride (50 wt% TDBAC, industrial) was further added. The grade was added dropwise and stirring was continued for 1 h to obtain a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic template was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-5.

Example 6

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 1.17 g of sodium hydroxide (96 wt% NaOH, technical grade), 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 37.06 g of distilled water, 5.14 g of white carbon black (98 wt%) SiO ₂ , technical grade) was uniformly mixed at 30 ° C, and 1.84 g of the directing agent prepared in the step (1) was slowly dropped into the mixture, and uniformly mixed. After stirring for 4 hours, 1.47 g of tetradecyldimethylbenzyl was further added. The ammonium chloride (50 wt% TDBAC, technical grade) was added dropwise and stirring was continued for 1 h to obtain a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic template was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-6.

Example 7

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt%) SiO ₂ , industrial grade) was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 1.17 g of sodium hydroxide (96 wt% NaOH, technical grade), 2.49 g of sodium metaaluminate (41.0 wt% Al ₂ O ₃ , technical grade), 24.10 g of distilled water, 18.00 g of tetraethyl orthosilicate ( 28wt% SiO ₂ , technical grade) was uniformly mixed at 30 ° C, and then 1.84 g of the guiding agent prepared in the step (1) was slowly dropped into the mixture, and the mixture was uniformly mixed. After stirring for 4 hours, 1.47 g of tetradecyldimethyl group was further added. The benzyl ammonium chloride (50 wt% TDBAC, technical grade) was added dropwise and stirring was continued for 1 h to give a viscous aluminosilicate gel.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. Thereafter, the organic templating agent was removed by calcination at 550 ° C for 8 hours in the air to obtain a mesoporous NaY zeolite molecular sieve, which was named MNY-7.

Comparative example 1

(1) 6.00 g of sodium hydroxide (96 wt% NaOH, technical grade), 1.24 g of sodium metaaluminate (41.0 wt% Al2O3, technical grade), 18.75 g of distilled water, 15.00 g of silica sol (30 wt% SiO2, industrial The mixture was uniformly mixed, ultrasonically shaken for 1 h, and stirred at 30 ° C for 20 h to obtain a NaY-type zeolite directing agent.

(2) 1.12 g of sodium hydroxide (96 wt% NaOH, technical grade), 2.49 g of sodium metaaluminate (41.0 wt% Al2O3, technical grade), 26.04 g of distilled water, 16.80 g of silica sol (30 wt% SiO2, industrial grade) The mixture was uniformly mixed at 30 ° C, and 1.84 g of the guiding agent prepared in the step (1) was slowly dropped thereinto, uniformly mixed, and after stirring for 4 hours, a viscous aluminosilicate gel was obtained.

(3) The material prepared in the step (2) is charged into a stainless steel reaction vessel containing a polytetrafluoroethylene liner, and crystallized at 80 ° C for 72 hours. After the crystallization is finished, the solid product is subjected to suction filtration, washing and drying. After that, it was calcined in air at 550 ° C for 8 h to obtain a microporous NaY zeolite molecular sieve, which was named NY-1'.

The structure and performance data of the NaY zeolite molecular sieves prepared in Examples 1 to 7 and Comparative Example 1 are shown in Table 1 below. The properties, structure and specific morphology of the NaY zeolite molecular sieve prepared in Example 3 are shown in Figures 1-4. Among them, the sample was characterized by Shimadzu LabX XRD-6000 X-ray diffractometer. The test conditions were: Cu target Kα radiation source, Ni filter, tube working voltage 40kV, tube current 30mA, scanning step length 0.02°, scanning range 5-35°, scanning speed 8°/min, room temperature; the results are shown in Figure 1. The sample shows the characteristic diffraction peak of typical NaY zeolite and matches the diffraction peak of ordinary NaY zeolite, indicating the product. There is a NaY-type zeolite phase. The surface morphology of the sample was characterized by a Japanese HITACHI S-4800 scanning electron microscope. The results are shown in Figure 2. The sample exhibited a uniform layered morphology.

The pore structure of the product was analyzed by a US ASAP 2020 N ₂ adsorption analyzer. As shown in FIG. 3, the mesoporous NaY zeolite molecular sieve of the present invention was in the low P/P ₀ region of 0.0<P/P ₀ <0.01. The amount of adsorption increases sharply with the increase of P/P ₀ due to the filling of N ₂ in the micropore region; a hysteresis loop occurs in the region of 0.4<P/P0<0.9, which is due to the capillary of N ₂ in the mesopores. Condensation; in the region of P / P ₀ > 0.9, the adsorption amount increases again, due to the adsorption of N ₂ in the macropores formed between the particles, indicating that the micro-middle-macropores in the sample coexist. 4 is a pore size distribution curve calculated according to the desorption BJH model, illustrating that the mesoporous NaY type zeolite molecular sieve of the present invention has a narrow mesoporous pore size distribution with an average pore diameter of 5.5 nm.

Table 1

Claims (11)

1. A method for preparing a medium pore NaY zeolite molecular sieve, comprising: the following steps:

   1) First mix the silicon source, aluminum source and water at 25-35 ° C, and adjust the pH to 9 ~ 12, then add the NaY molecular sieve guide agent into the mixture evenly, stir for 3 ~ 5h, then the organic season The ammonium salt is added dropwise as a template, and stirring is continued for 0.5 to 2 hours to obtain an aluminosilicate gel, the NaY type molecular sieve directing agent, the aluminum source, the silicon source, the templating agent and the water according to the final aluminosilicate gel system. the _{Na 2 O:Al 2 O 3 :SiO 2} : molar ratio of templating agent :H ₂ O ratio of 2.0 to 4.0:0.8 1.3:8.0 ~ ~ ~ 0.36:200 9.7:0.09 added to 240;

   2) the aluminosilicate gel is crystallized, the crystallization temperature is 60-90 ° C, the crystallization time is 72-120 h;

   3) The product of step 2) is calcined at 500-600 ° C for 4-8 h to remove the templating agent to obtain the mesoporous NaY zeolite molecular sieve.
2. The method for preparing a medium pore NaY type zeolite molecular sieve according to claim 1, wherein in the step 1), the preparation method of the NaY type molecular sieve directing agent is as follows: sodium hydroxide, sodium metaaluminate, silica sol and water by _{Na 2 O:Al 2 O 3 :SiO 2} :H 2 O molar ratio of 13.0 to 19.0:0.8 1.3:12.0 ~ ~ ~ 425.0 18.0:225.0 sufficiently mixed, and then aged at a temperature of 15 25 ~ 35 ℃ ~25h.
3. The method for preparing a medium pore NaY type zeolite molecular sieve according to claim 1 or 2, wherein in the step 1), the organic quaternary ammonium salt is tetradecyldimethylbenzyl ammonium chloride.
4. The method for preparing a mesoporous NaY zeolite molecular sieve according to claim 1 or 2, wherein in the step 1), the aluminum source is sodium metaaluminate, aluminum sulfate or aluminum nitrate.
5. The method for preparing a medium pore NaY type zeolite molecular sieve according to claim 1 or 2, wherein in the step 1), the silicon source is fumed silica, water glass, silica sol or ethyl orthosilicate. .
6. The method for preparing a mesoporous NaY zeolite molecular sieve according to claim 1 or 2, wherein in the step 2), the aluminosilicate gel is crystallized, followed by washing, filtering and drying. .
7. The method for preparing a medium pore NaY type zeolite molecular sieve according to claim 2, wherein in the preparation method of the NaY type molecular sieve directing agent, sodium hydroxide, sodium metaaluminate, silica sol and water are Na ₂ O Al ₂ O ₃ : SiO ₂ : H ₂ O is mixed at a molar ratio of 15.0 to 17.0:0.9 to 1.2:14.0 to 16.0:300.0 to 380.0.
8. The method for preparing a medium pore NaY type zeolite molecular sieve according to claim 2, wherein the aging time is 16 to 22 hours.
9. The method for producing a mesoporous NaY type zeolite molecular sieve according to claim 1 or 2, wherein in the step 2), the crystallization temperature is 75 to 85 ° C, and the crystallization time is 84 to 110 h.
10. The method for preparing a mesoporous NaY zeolite molecular sieve according to claim 1 or 2, wherein in the step 3), the calcination temperature is 530 to 580 ° C, and the calcination time is 5 to 7 h.
11. The method for preparing a medium pore NaY type zeolite molecular sieve according to claim 1 or 2, wherein in the step 3), the mesoporous pore size of the mesoporous NaY type zeolite molecular sieve is concentrated at 2.5 to 8.0 nm.

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